Not quite. This article talked about increase in HR, if yours is stable then this article's finding do not apply.

RHR has a genetic component - mine has already been low. When I was fit and getting enough sleep and stress free for an extended period of time, it was even lower.

I think of it as baseline RHR and relative changes to that baseline. Relative changes can be negative (as in RHR goes up) or positive (as in RHR goes down due to managing or removing stress, cardio and sleep).

If yours is 85 and you have room for improvement, then by all means you should try to bring in some positive RHR changes?